Part 5

Fraction 1. 0.1014 gram silver salt = 0.0785 gram silver = 76.3 per cent silver.

Fraction 2. 0.1000 gram silver salt = 0.077 gram silver = 77 per cent silver.

Fraction 3. 0.1116 gram silver salt = 0.0859 gram silver = 76.9 per cent silver.

Fraction 4. 0.1088 gram silver salt = 0.077 gram silver = 70.8 per cent silver.

Fraction 4 indicates the presence of formic acid, the silver salt of which requires, theoretically, 70.5 per cent of silver. Fractions 1, 2, and 3 indicate silver carbonate (which requires, theoretically, 78 per cent of silver) with a slight admixture of silver formate. The presence of silver carbonate was caused by a possible slight excess of sodium carbonate being added when the acid distillate was neutralized.

COMBINED ACIDS.

Saponification.--For the purpose of determining the acids held in combination in the oil in the form of esters, the oil was saponified with alcoholic potassium hydrate by heating on a water bath with a reflux condenser for one-half hour. Water was added to the mixture, and the oil separated in a layer. After removing the excess alcohol on a water bath, the alkaline solution was shaken out with ether to remove any adhering oil. The remaining solution was evaporated to a small volume, acidified with sulphuric acid, and distilled with steam.

The distillate from the above was extracted with ether and the ether evaporated spontaneously. Only a trace of an acid residue remained, which was neutralized with a solution of potassium hydroxid and precipitated in three fractions:

Fraction 1. 0.1012 gram silver salt = 0.0893 gram silver = 88 per cent silver.

Fraction 2. 0.0774 gram silver salt = 0.0637 gram silver = 82.3 per cent silver.

Fraction 3. 0.0758 gram silver salt = 0.0502 gram silver = 66.2 per cent silver.

The first two precipitates, when dried, consisted principally of silver oxid, which, theoretically, contains 89.2 per cent of silver. A slight excess of potassium hydroxid during neutralization was doubtless responsible. Fraction 3 would seem to point to the presence of acetic acid in the oil, silver acetate requiring 64.6 per cent of silver.

The aqueous acid portion remaining after the ether extraction was neutralized with sodium carbonate concentrated to small bulk and precipitated with silver nitrate in three fractions. Fraction 1 contained 76.2 per cent of silver; fraction 2, 77 per cent; and fraction 3, 74 per cent. Since silver formate contains 70.5 per cent of silver, a trace of formic acid is possibly present in the oil in combination.

The esters of the oil, as shown by the above results, are present in the oil principally as acetates, with a possible trace of formates.

FRACTIONATION OF THE OIL.

In order to ascertain the total percentage of camphor and to separate the remaining constituents as completely as possible, a quantity of the oil was fractionated into seven fractions, as follows:

Fraction 1, 160° C.; fraction 2, 160° to 170° C.; fraction 3, 170° to 178° C.; fraction 4, 178° to 182° C.; fraction 5, 182° to 186° C.; fraction 6, 186° to 190° C.; fraction 7, 190° to 195° C. These fractions (125 grams) were refractionated into 10 separate fractions, as shown in Table II, a determination of the physical properties of each fraction also being made.

+Table II.+--Fractionation of the oil of black sage, showing the physical properties of the fractions.

---------+------------+---------+--------+----------+-----------+------------- | |Distilled|Specific| Rotation |Re-fraction| Fraction.|Temperature.| over. | gravity|in 50 mm. | N{D} | Remarks. | | | at | tube. | 28° C. | | | | 26° C. | | | ---------+------------+---------+--------+----------+-----------+------------- |Degrees C.| Per | |Degrees.| | | | cent._ | | | | 1 |Below 160 | 2.5 | 0.8070 | + 6.9 | 1.4570 | Slight | | | | | |terebinthine | | | | | |odor. 2 |160 to 170 | 6.8 | .8768 | +10.1 | 1.4613 | Cineol-like | | | | | |odor. 3 |170 to 174 | 7.8 | .8865 | +10.1 | 1.4640 | Do. 4 |174 to 178 | 12.1 | .8920 | +10 | 1.4648 | Decidedly | | | | | |cineol-like | | | | | |odor. 5 |178 to 182 | 14.8 | .8996 | +10.2 | 1.4652 | Do. 6 |182 to 186 | 8.6 | .9077 | +11.5 | 1.4659 | Slight | | | | | |camphoraceous | | | | | |odor. 7 |186 to 190 | 8 | .9105 | +11.1 | 1.4673 | Strong | | | | | |camphoraceous | | | | | |odor. 8 |190 to 195 | 8.1 | .9130 | +11.7 | 1.4683 | Do. 9 |195 to 200 | 7.7 | .9170 | +11.6 | 1.4710 | Do. 10 |200 to 208 | 11.6 | .9220 | +10.4 | 1.4710 | Do. Residue |208 and | 12 | .9236 |..........| 1.4854 | Do. | above | | | | | ---------+------------+---------+--------+----------+-----------+-------------

IDENTIFICATION AND SEPARATION OF THE CONSTITUENTS.

Pinene.--The first fraction distilling below 160° C., and which possessed an odor of turpentine, was tested for pinene by means of the nitrochlorid reaction. A deep blue coloration was obtained with slight turbidity, indicating a possible trace of pinene.

Cineol, or eucalyptol.--Tests were made in fractions 2, 3, 4, 5, and 6 for cineol, which was easily recognized by its odor. For a qualitative test the iodol reaction was used, crystals of cineol iodol which melted at 111° to 112° C. forming in each fraction. Fractions 3, 4, and 5, which smelled strongly of cineol and which doubtless contained the major portion of cineol in the oil, were assayed by means of the phosphoric acid method, as directed in the United States Pharmacopœia for 1900. From these four fractions a total amount of 22.5 per cent of cineol was obtained, calculated from the original oil. This figure represents approximately the percentage of cineol in the oil, although it is low rather than high, since fractions 2 and 6 both showed the presence of cineol by qualitative tests, but the quantitative estimation in these fractions was impossible owing to the preponderance of other constituents in the fractions.

A test for terpinene in fraction 6, by means of the terpinene nitrosite reaction, produced a characteristic blue coloration, but the crystalline nitrosite would not separate.

Camphor.--A strong odor of camphor being distinguishable in fractions 7, 8, 9, 10, and in residue, a quantitative separation was made as completely as possible by means of the “freezing-out” method. Between 186° and 190° C. some crystals of camphor began to form in the inner tube of the condenser, and at 195° C. the condenser had to be kept jacketed with steam to prevent clogging, so rapidly did the camphor distill over. The fractions above 195° C. were practically solid. The camphor which separated at ordinary temperature was filtered on a force filter, and the liquid portion of the fractions subjected to freezing successively until camphor no longer separated. It is apparent that the separation of the camphor from these small fractions by freezing out is rather inaccurate because of the losses in transferring and filtering. From the above fractions, however, a quantity of camphor was obtained corresponding to about 40 per cent of the original oil. This figure is low, for the separation on a larger scale working with much larger fractions would reduce to a considerable degree the loss of camphor which is unavoidable in such small fractions.

The fractions distilling between 195° and 208° C. yielded crystals when treated with bromin in a petroleum-ether solution of the oil. The crystals melted at 130° C. Thujone tribromid melts at 122° C. A trace of thujone is therefore probably present in the oil. It is very possible, in view of the fact that the acetylization of the oil disclosed some free alcohol, that the last fraction contained some borneol, which boils at 212° C.

SUMMARY.

The results of the experiments would seem to indicate that the oil of black sage is composed essentially of camphor (more than 40 per cent) and cineol (22.5 per cent), with a small quantity of an alcohol, probably borneol, both free and as an ester, and a small quantity of the ketone thujone, with traces of the terpenes pinene and terpinene. Free formic acid was found, and only traces of combined acetic and formic acids in the form of esters.

The constituents of possible economic importance in the oil are camphor and cineol, both of which possess considerable medicinal value, the former being used also very extensively in the arts. These constituents, possessing strong antiseptic virtues, no doubt impart antiseptic properties to the oil. Inasmuch as the yield of oil from the fresh herb approximates 1 per cent, if distilled during the full flowering stage, and furthermore, since the plant thrives on low sandy hills or wastes, it is very probable that the shrub could be grown profitably both for its oil and for the large amount of camphor and cineol capable of being isolated from it.